Yes, it's intriguing, I know. What did happen to Melanie? One of the mysteries we'll never get to find out. Or will we?
I'm not all that keen myself, though. I'd rather the developer not put focus on any unnecessary side stories involving the other girls. It would just take up the developer's time, draw the story away from Monica, who, in my opinion, should have the major chunk--if not 100%--of the focus. This is her story, after all. Other girls' involvement should be restricted to furthering Monica's story--for example, a photoshoot with Melanie, or perhaps Julia (or someone else Monica's been mean towards) getting her "vengeance" with her. While I've no problems with other girls being in a game, I don't like it when the same girls divert the focus from the protagonist--especially when they steal sex scenes from the protagonist with their own little stories (as had happened with Kingdom of Deception, where Sabia, the protagonist, had started to get fewer and fewer sex time, which was taken up by other girls). We already have Fred dicking other girls in the game. I'd rather not have Melanie take up unnecessary story time, too.
That said, however, as I'd mentioned, if Melanie's story pertains to Monica--for example, some sort of deal she'd made at the farm involving Monica--then it's an entirely different thing. The same goes with Fred. Unless it's a future team-up with said girl against Monica (which I'm not aware of), I see no point to it. What deal did Melanie make at the farm? Now, that's a question that would intrigue me, if that's what did transpire at the farm. However, as far as "What happened to Melanie?" goes, I've not much interest in it.
Anyways, the next update's scheduled for September 8, so we'll soon find out about Melanie...or maybe not, depending on which way the developer swings. I'm really looking forward to this update, though. Going by the sample images, Monica's finally down to flashing her pussy and more. Plus, the update's bang in time for Fapping Sunday. That is, as long as the developer stays on schedule.